OK, take a deep breath and relax. You just need to get organized.
1. Take out 2 blank sheets of notebook paper. At the top of one, write "place 1," and on the top of the other one, write "place 2." Then, list information about the cultures in each of those places. This is where the research comes in. You'll just have to hit the books.
2. Take out a third sheet of paper. On the front, write "similarities," and on the back, write "differences." I think you know where I'm going with this. :) Go through the 2 lists with a fine-toothed comb, and list the similarities and differences.
3. Now, you need to choose only 3 things to compare/contrast.
For example:
(a) What is the attitude towards age?
(b) What is their concept of suffering or misfortune?
(c) How is their self-esteem?
(d) What is their attitude towards equality?
(e) What is their attitude towards nature and the Earth?
(f) What is their attitude towards food and fresh water?
4. These 3 things will be discussed in your 3 body paragraphs. One paragraph for each point.
Yes, you can definitely write "The Mayan culture is... whereas the Inca culture is..." when contrasting 2 points. Then, make sure you elaborate on each one. You will have to word it differently when comparing, of course.
Good luck!

You will have to do some research for that part. I listed some main points, above, that you can focus on while you research. For example, you can look into how the Myans treated their very young or elderly. Then, look into the same for the Incas.

If you are looking to start the introduction, you can say something like, "The cultural differences between the Myans and the Incas are numerous; however, surprisingly, there are several similarities as well.
Is that what you were looking for?

i can put paraphrase this info.or get little parts and put it in the intro for example i can say that the mayan culture lasted longer than the Incas..
"The main difference is that the Inca culture lasted for less than 200 years (A.D. 1440s-mid 1500s) in the present region of Peru, which is in South America, but the Mayan culture lasted for more than a thousand years, from about A.D. 400 to 1500, and flourished in the region of the Yucatan, which is in Mexico.
The Maya kingdom emerged around B.C. 1000, and lasted until A.D. 1697. All Maya shared a common culture and religion, but they did not have a capital city or ruler. Each city governed itself and had its own powerful ruler. The Maya had their own form of hieroglyphic writing."